Printing



Nov. 6, 1934.

J. ELMER ET AL PRINTING Filed Jan. 18, 1933 INVENTORS Jamv fLJljff? A ORPatented Nov. 6, 1934 UNITED STATES AT T cries PRINTING ApplicationJanuary 18, 1933, Serial No. 652,346

2 Claims.

This invention relates to a method of making blocks for block printing.More particularly, the invention relates to a method of making a Woodenblock having lines or pins formed thereon by saw cuts, and with portionscut away so as to leave only those parts of the pins or lines whichcorrespond to design areas upon which it is to apply a particular paint,or which it is desired to treat, as in a mashing operation, by burningtransverse grooves through the Wood of the lines or pins. In referringherein to printing blocks, or print-blocks, we include special blocks,e. 'g., so-called mash blocks, as well as those blocks which actuallyapply the paint or color.

Blocks of the general type referred to above are commonly used, forexample, in the printing of paint-coated felt base goods, printedlinoleums oil cloths and the like. In the manufacture of these blocks,it has been customary to form the designs by cutting away portions ofthe lines or pins with a sharp chisel. At best, this is a very delicateoperation. It frequently happens that the strain produced by the wedgingaction of the chisel breaks away portions of the line or pin whichshould have been left intact, and it is then necessary to replace thesebroken portions by brass pins, or other means, with considerable loss oftime, and in some cases with some impairment of the quality of the blockfor printing purposes. Particularly in the case where narrow portions ofthe lines or pins are to be left for the application of relatively smalldrops of paint, it is extremely difficult to cut away adjacent portionswithout injuring the part which is to be left intact. If it is brokenaway completely, it must be replaced with a brass pin, as describedabove, whereas if it is not broken away, but is cracked, it may be evenmore serious, because the defect may not appear until the block is onthe machine, whereupon the slight additional strain imposed in theprinting operation may be sufiicient to break the piece away from theblock.

It is an object of the present invention to provide a method of cuttingblocks such that even extremely fine projections may be formed for thecarrying of small drops of paint with little or no danger of injury. Itis another object of the invention to provide a method for cutting suchblocks which not only will result in a much superior block, but whichwill be quicker and easier to operate.

With these objects in view, the invention contemplates the forming ofthe designs on the print blocks by burning away portions thereof. In thepreferred form of the invention, this burning is accomplished by meansof an intense ccncentrated or focused narrow flame, for example, such asis produced by a small blow torch. The effect of such intense andlocalized heating is to burn away the narrow portion of the wood, uponwhich it' is concentrated, so rapidly that there is not sufficient timefor the heat to be transferred for any substantial distance through thewood so as to injure or seriously deteriorate the adjacent parts. Inthis way, a groove may be quickly out to follow any straight orirregular line in anydirection across or along the lines or pins of theblock, and although the sides of the groove will, of course, be charredby the heat, the charring does not extend for: any substantial distancebeyond the sides of the groove so that the adjacent portions of the pinor line, even though very narrow, will re'tain its strength sufficientlyfor all purposes of printing. Furthermore, the groove which results fromburning with a concentrated flame in this manner will be formed with arounded bottom, so that where very narrow remnants of the pin or lineare left beside such groove, they will, nevertheless, be much strongerthan would be formed by cutting a similar block with a chisel, becauseof the fact that the narrow top will be supported upon a base whichbroadens as it extends under the rounded bottom of the grooves.

Furthermore, since the groove is formed continuously by a steady andcontinuous movement of the flame over the block, the result is certainto be a continuous groove with the portion in each line or pinaccurately aligned with the portion in the adjacent lines or pins, andin this way, varied and irregular grooves are formed with the utmostsimplicity, whereas to obtain similar efiects by hand would involve along and tedious process, requiring the utmost care.

In the accompanying drawing, we have illustrated one method of applyingour invention:

In Fig. 1, we have shown in perspective a print block such as iscommonly used, upon which a design has been cut, and upon which a grooveis being formed in accordance with the present invention;

In Fig. 2 is shown a fragmentary view in perspective, upon a largescale, of a. portion of a line block having grooves formed therein byburning in accordance with the present invention.

In the block 10, as shown in Fig. l, the surface along the resultingline.

has first been grooved by forming shallow sawcuts 11 along closelyspaced parallel lines. The design is then drawn upon the block and thebroad outlines of the design are formed by cutting away with a chiselthe larger spaces indicated at 12. The narrow grooves 13, which in thiscase are used to simulate marble veining, are formed by burning inaccordance with the present invention, and to this end a blow-torch,which in the present case is indicated as a simple alcohol torch 14, isshown with its needle flame playing on the block, so that it is cuttingone of the grooves 13.

In Fig. 2, the groove which results from the burning is shown on anenlarged scale. As illustrated at 15, the bottoms of the grooves arerounded, and when close together will thus leave a narrow peaked, butbroad based, pin or remnant 16.

When a block such for example as that shown in Fig. 1, is used inprinting, narrow transverse grooves will be left in the paint coatingcorresponding to the grooves 13, and ifa different color is to beapplied in these grooves, a complementary block must be formed havinglines following the same paths as the grooves. In some cases, the narrowlines of these complementary blocks may be formed by burning grooves oneither side of the line, and then cutting away, wherever necessary, witha chisel beyond the grooves. Ordinarily, however, it will be mostsatisfactory and economical to form cast metal lines which may besecured to blocks in the usual manner used to print the narrow linescorresponding to the grooves.

These metal lines are commonly formed by burning into solid woodenblocks grooves as nearly as possible along the same paths as the groovesburned in the line blocks. In this case,

'it is preferable, where possible, to burn the grooves by means ofheated blades, since the depth of the groove in this way can be morereadily controlled, and the metal, when cast, may therefore be ofsubstantially uniform depth Where extremely irregular lines are to beformed, however, the direct flame-burning method, as described above,

may be used for forming the matrix in which the typemetal is cast. Inthis case, the flame should be adjusted as narrow as possible, and theburning should preferably be somewhat deeper than in burning grooves onthe line blocks. Where extremely irregular lines are to be used, so thatit may be difficult to reproduce a line exactly, the groove may beburned into the solid block as already described, and the metal castinto this block as a matrix. The metal in this case should, of course,be one which melts at a relatively low temperature, so that the block isnot injured by the heat of the metal. If the surface should be charredto any substantial extent, the charred portion should be planed OE, andthereafter saw cuts may be formed, and the remainder of the design cutout in the usual way.

In the above, we have given a preferred embodiment of our invention andvarious modifications thereof, in order to illustrate its principle andapplication. It is to be understood, however, that these are intended tobe exemplary only, and that many other changes and modifications may bemade without departing from the scope of this invention.

We claim:

1. The method of forming a print block for a pattern having relativelynarrow lines thereon which comprises cutting the broader outlines of thepattern from the wood block and forming said narrow lines by burning thewood therealong by means of a narrow focused intense flame.

2. The method of forming a printing block for a pattern havingrelatively narrow lines thereon which comprises cutting the broaderoutlines of the pattern from the wood block and forming a narrowtransverse portion of a line or a pin by cutting at least one sidethereof with a flame whereby said narrow portion may be freed from anadjacent portion without subjecting it to any strain and whereby saidremaining portion will be formed narrow at the top with a broadenedbase.

JOHN ELMER. BERNARD J. KELLY.

